Password Hashing Funzioni
PHP Manual

password_hash

(PHP 5 >= 5.5.0)

password_hashCreates a password hash

Descrizione

string password_hash ( string $password , integer $algo [, array $options ] )

password_hash() creates a new password hash using a strong one-way hashing algorithm. password_hash() is compatible with crypt(). Therefore, password hashes created by crypt() can be used with password_hash().

The following algorithms are currently supported:

Elenco dei parametri

password

La password dell'utente.

Attenzione

Using the PASSWORD_BCRYPT for the algo parameter, will result in the password parameter being truncated to a maximum length of 72 characters.

algo

Una costante per l'algoritmo della password che stabilisce l'algoritmo da utilizzare quando si effettua l'hashing della password.

options

Un array associativo che contiene opzioni. Attualmente, sono accettate due opzioni: salt, per fornire un sale da usare al momento dell'hashing della password, e cost, che stabilisce il costo algoritmico che deve essere utilizzato. Degli esempi di questi valori si trovano alla pagina crypt().

If omitted, a random salt will be created and the default cost will be used.

Valori restituiti

Returns the hashed password, o FALSE in caso di fallimento.

The used algorithm, cost and salt are returned as part of the hash. Therefore, all information that's needed to verify the hash is included in it. This allows the password_verify() function to verify the hash without needing separate storage for the salt or algorithm information.

Esempi

Example #1 password_hash() example

<?php
/**
 * We just want to hash our password using the current DEFAULT algorithm.
 * This is presently BCRYPT, and will produce a 60 character result.
 *
 * Beware that DEFAULT may change over time, so you would want to prepare
 * By allowing your storage to expand past 60 characters (255 would be good)
 */
echo password_hash("rasmuslerdorf"PASSWORD_DEFAULT)."\n";
?>

Il precedente esempio visualizzerà qualcosa simile a:

$2y$10$.vGA1O9wmRjrwAVXD98HNOgsNpDczlqm3Jq7KnEd1rVAGv3Fykk1a

Example #2 password_hash() example setting cost manually

<?php
/**
 * In this case, we want to increase the default cost for BCRYPT to 12.
 * Note that we also switched to BCRYPT, which will always be 60 characters.
 */
$options = [
    
'cost' => 12,
];
echo 
password_hash("rasmuslerdorf"PASSWORD_BCRYPT$options)."\n";
?>

Il precedente esempio visualizzerà qualcosa simile a:

$2y$12$QjSH496pcT5CEbzjD/vtVeH03tfHKFy36d4J0Ltp3lRtee9HDxY3K

Example #3 password_hash() example setting salt manually

<?php
/**
 * Note that the salt here is randomly generated.
 * Never use a static salt or one that is not randomly generated.
 *
 * For the VAST majority of use-cases, let password_hash generate the salt randomly for you
 */
$options = [
    
'cost' => 11,
    
'salt' => mcrypt_create_iv(22MCRYPT_DEV_URANDOM),
];
echo 
password_hash("rasmuslerdorf"PASSWORD_BCRYPT$options)."\n";
?>

Il precedente esempio visualizzerà qualcosa simile a:

$2y$11$q5MkhSBtlsJcNEVsYh64a.aCluzHnGog7TQAKVmQwO9C8xb.t89F.

Example #4 password_hash() example finding a good cost

<?php
/**
 * This code will benchmark your server to determine how high of a cost you can
 * afford. You want to set the highest cost that you can without slowing down
 * you server too much. 8-10 is a good baseline, and more is good if your servers
 * are fast enough. The code below aims for ≤ 50 milliseconds stretching time,
 * which is a good baseline for systems handling interactive logins.
 */
$timeTarget 0.05// 50 milliseconds 

$cost 8;
do {
    
$cost++;
    
$start microtime(true);
    
password_hash("test"PASSWORD_BCRYPT, ["cost" => $cost]);
    
$end microtime(true);
} while ((
$end $start) < $timeTarget);

echo 
"Appropriate Cost Found: " $cost "\n";
?>

Il precedente esempio visualizzerà qualcosa simile a:

Appropriate Cost Found: 10

Note

Attenzione

It is strongly recommended that you do not generate your own salt for this function. It will create a secure salt automatically for you if you do not specify one.

Nota:

It is recommended that you test this function on your servers, and adjust the cost parameter so that execution of the function takes less than 100 milliseconds on interactive systems. The script in the above example will help you choose a good cost value for your hardware.

Nota: Updates to supported algorithms by this function (or changes to the default one) must follow the following rules:

  • Any new algorithm must be in core for at least 1 full release of PHP prior to becoming default. So if, for example, a new algorithm is added in 5.5.5, it would not be eligible for default until 5.7 (since 5.6 would be the first full release). But if a different algorithm was added in 5.6.0, it would also be eligible for default at 5.7.0.
  • The default should only change on a full release (5.6.0, 6.0.0, etc) and not on a revision release. The only exception to this is in an emergency when a critical security flaw is found in the current default.

Vedere anche:


Password Hashing Funzioni
PHP Manual